Ozone is an unstable gas with a half life of less than one hour at room temperature. The methods used to convert oxygen to ozone involve high voltage corona discharge or ultraviolet light. Ozone generators have been available for decades for industrial uses. Indeed, ozone is a powerful oxidizer and has been used for deodorizing air, and purifying water. It is a known bactericide and viricide and recently has been used to sterilize medical instruments; although, the cycle times are so long as to be impractical for many uses.
Ozone generators have been used for therapeutic applications for several years. Such applications include but are not limited to autohemotherapy, rectal insufflations, intradiscal injection and full body exposure. Ozone has also been used to treat diffuse bulging or contained herniation of the spinal disc.
Spinal discs are composed of a fibrous outer ring made of Type I collagen and a softer more flexible nucleus made of Type II collagen, proteoglycans and water. Patients with disc bulging or herniation suffer from pain caused by disc compression of the neurological elements, including the spinal cord, cauda equina and nerve roots. Intradiscal ozone treatment involves direct injection of a gaseous mixture of oxygen and ozone into the nucleus of the disc. Ozone releases water from the proteoglycans, reducing disc size and relieving compression of neurological elements. Some investigators believe that ozone stimulates anti-inflammatory mediators and initiates a healing response.
The mechanism of action and reported success rates of ozone treatment are similar to that of the enzyme chymopapain. Chymopapain was first FDA-approved in 1983 and was widely used with a success rate of 65-85%. A small number of serious complications, including death and paralysis, caused the product to lose favor in the market and the product was eventually discontinued in the United States.
Ozone and chymopapain are two means of performing a chemical discectomy through a needle puncture. This minimally invasive approach may be preferred to surgical discectomy, which requires general anesthesia and direct access to the spinal disc.
Therapeutic ozone must be delivered immediately after being produced. Existing medical ozone generators pass medical oxygen through an electric field or ultraviolet light. This process converts an amount of oxygen into ozone. A syringe is interfaced with the machine whereby ozone is withdrawn for subsequent use in chemical discectomy.
The preferred concentration of ozone for this application is less than 6%. The concentration of ozone is important for medical uses. If the concentration is too low the treatment will not be effective; if the concentration is too high detrimental effects may follow. As such, medical ozone generators must include a means for measuring the concentration of ozone. The elements necessary to create and measure ozone are sensitive and require maintenance to ensure precise and accurate operation.
Present ozone generators have basic means for controlling the concentration and delivery of ozone gas. Oxygen is generally passed through a machine containing permanent electrodes; the gas chambers of present generators are often permanent as well. Some generators include components that neutralize excess ozone. Others generators continuously vent ozone, while still others are self-contained within a syringe, offering little means for measuring or controlling the concentration of ozone gas. Present ozone generators often include components for gas containment or pass oxygen through reaction chambers that are permanent and reusable, lending to sterility issues. Medical professionals often inject the gas through a bacterial filter to address such sterility issues.
Present generators are capable of offering a minimally invasive medical procedure to patients currently in need of surgical discectomy. Present generators lack an ozone delivery system that can efficiently provide sterile unit doses of ozone. Further, current systems lack the ability to ensure sterility and purity of the ozone dose, have high maintenance costs, fail to address problems associated with degradation of corona discharge mechanisms, and have inefficiencies associated with excessive production of ozone that must be neutralized through a catalytic converter.